Achieving quality sound presentation in high-noise environments, such as moving vehicles, remains particularly challenging. For example, the bass response of a system in such an environment is generally inadequate. While the bass response may be boosted with an equalizer to compensate for this inadequacy, this approach typically causes a muffled treble response, thus diminishing the sound quality. In addition to a muffled treble, bass boosting may undesirably increase the dynamic range of the sound presentation. In a noisy environment, there is very little audio range between the volume floor set by the noise (typically around 80 dB in moving vehicles) and the volume ceiling set by the physiology of the ear (typically around 110 dB). Increasing the dynamic range of sound presented in a noisy environment may be aesthetically undesirable because the sound level may approach the ear's physiological volume ceiling, resulting in an unpleasant, annoying, or even painful response. Accordingly, a new approach is needed for quality audio presentation in a high-noise environment.
Typical consumer sound transducers, such as commercial speakers, are acoustically efficient between approximately 600 and 1,000 cycles. To compensate for the inefficient performance of such transducers outside this range, systems often employ a variety of special speakers and amplifiers that can be quite expensive. A system that compensates for this inefficient performance without the introduction of extra and often expensive hardware would be beneficial.
Today, the dynamic range of sound in motion pictures is created and mixed in an environment the size of a movie theater. Quality playback of motion picture audio in a small environment, such as a home entertainment area or an automobile, is difficult at best. In a small environment, audio standing waves often develop, producing an annoying acoustical signal at the frequency of the standing wave. Compensation for such specific standing waves in a given small environment would produce a higher quality audio presentation.
Finally, in contrast to the careful attention given to movie sounds and music, the audio in electronic video games are often mixed haphazardly. This haphazard mixing often does not present full, balanced audio to the listener. Enhancing the audio signal frequency wide across the full dynamic range will present higher quality audio.